Various forms of squares including relatively pivotal arm portions heretofore have been provided such as those squares disclosed in U.S. Pat. Nos. 973,437, 1,324,411, 1,646,958 and 1,663,821. In addition, various of these squares are provided with spirit levels and many include structure whereby the arms may be releasably secured in adjusted angularly displaced positions.
However, many of these previously known forms of squares are not constructed in a manner whereby the pivotally connected arms thereof may be relatively angularly displaced a full 360.degree. and some do not include structure whereby the arms thereof may be releasably secured in numerous different relatively angularly displaced positions. Also, it is often desirable to indicate aligned line segments on opposite sides of a line intersecting the ray of the line segments and many previously known forms of squares are not capable of being used in this manner. Accordingly, a need exists for an improved form of square.